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<body><h1><a href="http://ejohn.org/blog/processingjs/">Processing.js</a></h1>
<h2>VariableScope</h2>

<p>Variables may either have a global or local "scope". 
For example, variables declared within either the
setup() or loop() functions may be only used in these
functions. Global variables, variables declared outside
of setup() and loop(), may be used anywhere within the program.
If a local variable is declared with the same name as a
global variable, the program will use the local variable to make 
its calculations within the current scope. Variables may be localized
within classes, functions, and iterative statements.</p>

<p><a href="http://processing.org/learning/basics/variablescope.html"><b>Original Processing.org Example:</b> VariableScope</a><br>
<script type="application/processing">
int a = 20;  // Create a global variable "a"

void setup() 
{
  size(200, 200);
  background(51);
  stroke(255);
  noLoop();
}

void draw()
{
  // Draw a line using the global variable "a"
  line(a, 0, a, height);
  
  // Create a new variable "a" local to the for() statement 
  for(int a=50; a<80; a += 2) {
    line(a, 0, a, height);
  }
  
  // Create a new variable "a" local to the loop() method
  int a = 100;
  // Draw a line using the new local variable "a"
  line(a, 0, a, height);  
  
  // Make a call to the custom function drawAnotherLine()
  drawAnotherLine();
  
  // Make a call to the custom function setYetAnotherLine()
  drawYetAnotherLine();
}

void drawAnotherLine() 
{
  // Create a new variable "a" local to this method
  int a = 185;
  // Draw a line using the local variable "a"
  line(a, 0, a, height);
}

void drawYetAnotherLine() 
{
  // Because no new local variable "a" is set, 
  // this lines draws using the original global
  // variable "a" which is set to the value 20.
  line(a+2, 0, a+2, height);
}
</script><canvas width="200" height="200"></canvas></p>
<div style="height:0px;width:0px;overflow:hidden;"></div>

<pre><b>// All Examples Written by <a href="http://reas.com/">Casey Reas</a> and <a href="http://benfry.com/">Ben Fry</a>
// unless otherwise stated.</b>
int a = 20;  // Create a global variable "a"

void setup() 
{
  size(200, 200);
  background(51);
  stroke(255);
  noLoop();
}

void draw()
{
  // Draw a line using the global variable "a"
  line(a, 0, a, height);
  
  // Create a new variable "a" local to the for() statement 
  for(int a=50; a&lt;80; a += 2) {
    line(a, 0, a, height);
  }
  
  // Create a new variable "a" local to the loop() method
  int a = 100;
  // Draw a line using the new local variable "a"
  line(a, 0, a, height);  
  
  // Make a call to the custom function drawAnotherLine()
  drawAnotherLine();
  
  // Make a call to the custom function setYetAnotherLine()
  drawYetAnotherLine();
}

void drawAnotherLine() 
{
  // Create a new variable "a" local to this method
  int a = 185;
  // Draw a line using the local variable "a"
  line(a, 0, a, height);
}

void drawYetAnotherLine() 
{
  // Because no new local variable "a" is set, 
  // this lines draws using the original global
  // variable "a" which is set to the value 20.
  line(a+2, 0, a+2, height);
}</pre>
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